I plan to do some flow next week and an one of the steps is to resuspend the bacterial pellet to an OD600 0.5. So say I had a 1.5mL overnight culture and the following morning the OD600 was 1.7. Once I spin down, wash etc etc I read to get to a certain OD (0.5 in my case)...this is the calculation

Divide the OD you want (0.5) by the OD bacteria was at in morning (1.7)=0.5/1.7=0.29=giving you a concentration factor (cf)

Divide the original culture volume (1.5mL) by the cf

1.5/0.29=5.1mL

Ok..so I don't need 5.1mL of culture to subsequently use..say altogether I only need 2mL how do I go about this? So that in the end I have 2mL of bacteria with an OD of 0.5?

Is this way better..say I had the a 10mL of o/n starter cultureI take 1mL from that starter culture, wash, spin, block etc..and when it comes down to resuspending my pellet..i resuspend in 1.5mL again..therefore I technically have a culture at an OD600 of 1.7.

From that culture which I just resuspended in...can I take 441uL and then top up 2mL using 1559uL of my buffer?